1. Field of the Invention
The present invention relates to a shielded socket for an electrical device, and more particularly, to a shielded land grid array (LGA) socket.
2. Discussion of Related Art
The ongoing trend toward increased performance and higher density electrical circuits has led to the development of surface mount technology in the design of electronic packages and printed circuit boards (PCBs). As the amount of memory increases in electronic systems so does the amount of bandwidth required for the processors, and resultantly the number of in/out (I/O) connections.
Sockets are commonly used to enable multiple insertions of packages onto PCBs (e.g. mother boards) or other substrates. Due to the close proximity of the I/O connections to each other crosstalk has become an important performance issue. Crosstalk results from the coupling of the electromagnetic field surrounding an active conductor into an adjacent conductor. In addition, matched impedance for socket contacts is desired to minimize signal reflections which can result in false triggering or missed triggering of devices.
Conventional socket improvement is based on redesigning the socket geometrical shape. This involves long socket design and validation processes, does not provide optimal electrical performance, and is not friendly to socket persistence over generations. Contact to contact isolation is generally achieved by assigning a number of contacts as ground. Isolation is not ideal due to the contact geometry limitation and insufficient signal contact to ground contact ratio.